[Samba] NT sid mapping to uid,gid.

[Meli Marco]

Hi all,
I have the following situation:
1 PDC Windows NT 4.0.
1 Samba server Member Domain connect to PDC via winbind.
1 Rsync server connect to Samba server Member Domain.
Now, I would like to know how can I share SID mapping on UID/GID in Samba
because I have to install another Samba on Rsync server and in case of
emergency switch to this one.
Maybe I have to use LDAP server as backend in actually Samba server, and
connect future Samba/Rsync server to this one but I don't understand how can
I do it and if it is correct with LDAP or does it works only with an AD
server?
Can I use winbind to ask to the NT/PDC and populate an LDAP containerin the
same server? 
Can anyone help me?
Thanks a lot.
Tito.